Estimation of Gentic and Phenotypic Parameters for some Productive and Reproductive Traits in Egyptian Buffoloes

Abstract

The present study aimed to display effects of age at first services, age at first calving (AFC), calving interval, days open, number of services per conception, days dry, season of calving on total milk yield (TMY) and 305 milk yield (305MY). Also, to estimate effect of season and parity on calving interval (CI) and days open and then the effect of level of production on service per conception, age at first service, age at first calving, calving interval and days open. Heritability estimates for 305-day milk yield (0.18), days open (0.18), dry period (DP) (0.12), TMY (0.17) and CI (0.19). High heritability estimates were obtained for AFC (0.68) and lactation length (LL) (0.78). There were high positive genetic and phenotypic correlations between total milk yield and 305-day milk yield and low genetic and phenotypic correlations between most studied traits. Average EBV for AFS, AFC and 305MY were higher in cow than sire and dam. Also, average EBV for LL and DO were higher in sire than in cow and dam and average EBV for CI and DP were higher in dam than in cow and sire. But TMY was equal in sire and dam and higher than cow.

Determination of Direct and Indirect Effects on Milk Yield of Anatolian Buffaloes Using Path Analysis

“…The correlation between LMY and LL was 0.67 in Anatolian buffaloes (Öz et al, 2022), 0.56 in Nili Ravi buffaloes (Tamboli et al, 2021), 0.89 in crossbred buffaloes (Malhado et al, 2009), 0.39 and 0.71 in Murrah buffaloes (Suhail et al, 2009;Jakhar et al, 2017), and 0.72 in Murrah and Murrah crossbreeds (Rodrigues et al, 2010). The LMY and LL correlation of 0.697 in the study was higher than the values determined by Malhado et al (2013) for Murrahs, Abo Gamil et al (2017) for Egyptian buffaloes, Barros et al (2016) for Murrah crossbreeds, and Tamboli et al (2022) for Murrah crossbreeds, but it was compatible with the values determined by Rodrigues et al (2010) for Murrah and Murrah crossbreeds and Kumar et al (2022) for Murrah buffaloes. As is known, there is a linear relationship between LL and LMY.…”

GENETIC ASSESSMENT AND TRENDS FOR MILK PRODUCTION TRAITS IN A HERD OF EGYPTIAN BUFFALOES (Bubalus bubalis)

“…In Egyptian buffalo, rg among MY traits were highly positive, as estimated between MY and FY(0.997 ±0.131), MY and PY(0.986 ±0.142), and FY and PY(0.993 ±0.140)(El-Bramony, 2015), and recorded 0.87 between TMY and 305-MY (Abo-Gamil et al, 2017). In addition, it was estimated 0.98 between MY and FY, 0.99 between MY and PY, 0.99 between FY and PY(El-Bramony et al, 2010a).Moreover, it was recorded 0.18 ±0.09, 0.30 ±0.10, and 0.37 ±0.09 between TMY, and each of FY, PY, and LY, respectively (El-Bramony et al, 2010a).…”

“…The rp's among TMY, MY, FY, PY, LY, TSY, and SNFY were positive and ranged 0.318 to 0.449. In Egyptian buffalo, high positive rp was estimated to be 0.94, 0.89 and 0.85between MY and FY, MY and PY, and FY and PY, respectively(El-Bramony et al, 2010a);and rp among TMY and each of FY and PY were ranged from 0.944 to 1 (El-Bramony et al, 2010b);and between MY and FY was 0.956 and between PY and FY was 0.947 (El-Bramony, 2015).In addition, rp was estimated to be 0.77 between TMY and 305-MY (Abo-Gamil et al, 2017). Therp between TMY, and each of FY, PY, and LY were positive and being 0.64, 0.63 and0.53, respectively.…”